Biogeographic trends in Antarctic lake communities

• Main Authors: Gibson, John, Wilmotte, Annick, Taton, Arnaud, Van de Vijver, Bart, Beyens, Louis, Dartnall, H. J. G.
• Format: Book Part
• Language: English
• Published: Springer 2006
• Subjects: cyanobacteria; Biogeography; Antarctic; lakes; Life sciences; Microbiology; Environmental sciences & ecology; Sciences du vivant; Microbiologie; Sciences de l’environnement & écologie; Antarc*; Antarctica; Macquarie Island
• Online Access: https://orbi.uliege.be/handle/2268/17382; https://doi.org/10.1007/1-4020-5277-4_5

The basic biogeographic zones proposed many years ago – the Subantarctic islands, Maritime Antarctica and Continental Antarctica – continue to hold up, though they cannot be seen as absolute dividers of biodiversity. For example, subantarctic Macquarie Island appears to be biogeographically separate from the islands of the Kerguelen Province, and on the continent there are species that are present in lakes of more than one zone. Furthermore, there are numerous lake environments that have yet to be investigated, and it is probable that some of these lakes could turn up surprises that will bring into question these basic divisions. An important question to be answered is whether these biogeographic zones reflect climate attributes, or whether they were moulded long ago by barriers to dispersal. Again, our imperfect knowledge of Antarctic lacustrine biogeography means that this question cannot at present be answered. However, as discussed elsewhere in this volume (Chown and Convey), there are indications of a strong biogeographical boundary for terrestrial species between the Maritime and Continental Antarctic zones. A palaeolimnological approach will assist in answering this question: understanding how Antarctic biogeography has developed through time will provide necessary insights into current distributions. A prime example is the occurrence of the copepod Boeckella poppei in Beaver Lake. Pugh et al. (2002) initially concluded that this species was an anthropogenic introduction, then Bayly et al. (2003) provided morphological evidence for long habitation in the area of Beaver Lake. Recent palaeolimnological work has shown that the species has been present in nearby Lake Terrasovoje for at least 9000 yrs (L. Cromer, A. Bissett, J. Gibson and K. Swadling, unpublished data). Even though this lake has only existed in the Holocene, cosmogenic exposure dates in the same area of exposed rock can exceed 106 years (D. Gore and D. White, personal communication). From these observations it can be concluded that Boeckella ...